• Touchpads are reasonable and readily available for most types of electronic equipment.Staying in Touch image by Kathy D from Fotolia.com
  
  A touchpad is a simple, easy and reasonable pointing device. Touchpads can be used on a variety of electronics and are available on nearly all interfaces. These devices are designed within the equipment or installed with a simple plug-in. Costs of input devices are reasonable because they are widely available with several options to chose from, with some having the ability to be purchased over-the-counter or online.
  
  

Resistive

• A resistive touchpad allows the users to use equipment to touch the screen or application. Resistive touchpads, however, don't allow the user to use his fingers to activate the touchpad capability. For example, resistive touchpads may be used for personal digital assistants, electronic dictionaries and books or PC tablets. This may call for a stylus or other instrument to activate the touchpad. Resistive touchpads have two membranes---top and bottom. The object applies pressure to the screen, activating the top membrane. The top membrane then applies pressure to the underlying membrane. The controller in the device recognizes the two membranes are connecting to each other and it allows the touchpad to function.
  
  

Electromagnetic

• The electromagnetic touchpad works much like the resistive touchpad. This touchpad is also operated by an instrument. The instrument is different than a stylist used in resistive touchpads because the electromagnetic touchpad is operated by a light pen. A pen-like instrument uses a point of light to make contact with the screen. Electromagnetic touchpads are less preferred when compared to a resistive touchpad because the light must hit specific points to operate correctly. If it does not make specific contact, it will not allow access to the screen.
  
  

Capacitive

• The capacitive touchpad is highly preferred over resistive and electromagnetic touchpads. Capacitive touchpads may be used for public access to Internet, guiding systems or cell phones. For instance, a touch screen may be in place for self bill payment centers or self-checkout. In the capacitive touchpad, an electronic field is placed above the equipment. When fingers touch the mechanism, it changes the electrical field for the touch screen to operate.
  
  These devices are preferred over other because the pressure point does not have to be so focused as other touch-pads. They also call for simple construction, fewer components and yield higher production. Capacitive are very versatile as they can operate on compact, mountable or surfaces that are movable.